Shahab Alizadeh - Department of Cellular and Molecular Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences (TUMS), Tehran, Iran

Background: Emerging evidence has shown that obesity has different phenotypes and a subset of obese individuals, known as metabolically healthy obese (MHO) subjects, might be at lower risk for developing obesity-derived complications than their metabolically unhealthy obese (MUHO) peers. Although most previous studies have linked obesity to chronic kidney disease (CKD), reports regarding the association between MHO phenotype and risk of CKD are inconsistent. This meta-analysis was conducted to comprehensively analyze the risk of CKD in different phenotypes of body size. Methods: The EMBASE, MEDLINE, and Web of Science databases were systematically searched until May 2016 to identify all prospective cohort studies exploring CKD risk associated with metabolic phenotypes of body size. Body size phenotypes were defined based on the combination of the presence/absence metabolic syndrome and categories of body mass index. The estimated risks and 95% confidence intervals (CIs) were extracted and pooled using a random-effects model. Results: A total of 7 studies, with 3596 cases and 142824 participants were included in the meta-analysis. The analysis revealed that individuals with metabolically healthy obesity were at increased risk for CKD compared with healthy normal-weight participants (OR =1.45; CI =1.26-1.64, fixed effects), but had lower risks than metabolically unhealthy obese (OR =2.04, 95%CI =1.40–2.68, random effects) individuals. In addition, normal-weight individuals with metabolically unhealthy status had almost similar risk for CKD as those with metabolically healthy obesity phenotype (OR =1.44, 95%CI =1.16–1.72, fixed effects). Conclusion: These findings suggest that persons with metabolic aberrations, however at normal-weight, have an increased risk for incident CKD. Healthy obese subjects had higher risk; refuting the notion that metabolically healthy obesity is a benign condition.

Obesity, chronic kidney disease, meta-analysis